An electronic device test system conveys a large number of ICs held on a tray inside a handler, brings the ICs into electrical contact with sockets of a HiFix of a test head, and uses a tester to test them. Further, after finishing the tests, the ICs are classified into corresponding customer trays based on the categories of the test results.
A HiFix (interface apparatus) which relays electrical connections between the ICs under test which sides with the handler and the test head is mounted on the top of the test head. Further a DSA (device specific adapter) is mounted on the top of this HiFix. This DSA has a socket board etc. on which sockets are mounted for electrical contact with the input/output terminals of the ICs under test. This DSA is prepared in a variety of types in accordance with the types of the IC chips under test and has to be changed along with a change in the type of the IC chips. For this reason, a DSA attachment apparatus for attaching or detaching the DSA to or from the HiFix body is provided at the HiFix body.
As such a DSA attachment apparatus, a DSA attachment apparatus 540 using a cam mechanism shown in FIG. 13 and FIG. 14 has been known in the past. This attachment mechanism 540 comprises: a cam 542 attached to a linearly moving drive shaft 541a of an air cylinder 541; and a cam follower 545 attached to an engagement shaft 544 engageable with the DSA 501. Further, by the cam follower 545 rolling along a cam groove 543 formed at the cam 542 at a slant and the engagement shaft 544 engaged with the DSA 501 linearly moving in the downward direction, the DSA 501 is attached to the HiFix body 510. As opposed to this, by the engagement shaft 544 engaged with the DSA 501 moving linearly along the upward direction, the DSA 501 is detached from the HiFix body 510.
By the way, when attaching the DSA to the HiFix body, their connectors are coupled together whereby the DSA and the HiFix body are electrically connected. For that reason, for attachment, a predetermined force is required for coupling the connectors together. The number of connectors increases along with the increase of the number of simultaneous measurements in electronic device test systems in recent years and the force required for pushing the DSA toward the HiFix body at the time of attachment tends to increase.
In order to deal with this trend toward increase of the pushing force by the above mentioned DSA attachment apparatus 540 utilizing a cam mechanism, it is necessary to lengthen the cam groove 543 to increase the reduction ratio or increase the number of attachment apparatus. Further, in the above DSA attachment device 540, the drive force supplied from the air cylinder 541 is transmitted through linear contact of the cam follower 545 and the cam groove 543, so it is not possible to deal with the increase in pushing force unless strengthening the structure of the cam 542 and cam follower 545. For this reason, an increase in size of the attachment apparatus and higher costs are invited.